The Academy of Motion Picture Arts and Sciences is aiming to expand and diversify its ranks by relaxing a cap on membership that has restricted new admittances since 2004.

The academy has about 5,800 voting members; in recent years, fewer than 200 people have been invited to join annually. The number of openings is essentially determined by how many members have retired, resigned or died. In the last decade, the overall ranks have not grown by more than 30 members a year.

Academy leaders say they are not loosening the qualifications for membership. Rules state that there are three ways to become eligible for admittance: an Oscar nomination, a recommendation from two members of the applicant's branch, or an endorsement by the branch's membership committee and staff.

It is unclear just how many new members the academy will invite this year, and when and how the policy change was arrived at. An academy spokeswoman said Friday that the change was recommended last fall to the Board of Governors by the general membership committee.

It appears the change will start to take effect next month, when membership committees from each of the group's 15 branches meet to begin reviewing invitations for 2013. Last June, the academy invited 179 new members.

Sound branch member Don Hall, who is on the Board of Governors, said it's a good move that will allow a greater number of accomplished people in his technical field to be recognized. "We can now invite in others who haven't won awards but are just as deserving," he said. "Without the quota, we can get them in."

The academy has periodically faced calls to diversify its ranks. A 2012 L.A. Times study found that nearly 94% of academy voters are white and 77% are male. Blacks make up about 2% of the academy and Latinos less than 2%. Oscar voters have a median age of 62, the study showed.

Between 1990 and 2000, the academy added nearly 800 net new members. The group put the brakes on membership growth prior to issuing invites in 2004 after then-executive director Bruce Davis alerted the Board of Governors to a steep increase in the ranks despite no commensurate growth in the film business.

"For most organizations, becoming larger is an unalloyed good, an objective hotly pursued," the academy said in a 2007 report. "For a group made up of distinguished contributors to an art form though, there is a case to be made for selectivity trumping growth."

More recently, though, academy leaders, including Chief Executive Dawn Hudson and past president Tom Sherak, have said they have been trying to diversify the membership. But change has been difficult, they have said, because the film industry is not very diverse in the first place, and slow because the academy has been limiting membership growth for the last decade.

One member who is familiar with the invitation process but asked not to be named because he was not authorized to speak by academy officials said in recent years branch membership committees often would not even fill the number of slots they were allocated by academy leaders.

A member of the producers branch, who asked that his name not be used, said this week he wasn't sure how much of an immediate effect the relaxation of the membership cap would have in his division.

"I suspect we will be pretty self-limiting in terms of who we take in, in large part because the people on our membership committee have produced a lot of movies and want to keep the academy a merit-based organization," he said. He added that in order to be eligible for admission to the producers branch, a prospective member must have two full producing credits on "works of a particular value."